Phonograph system

ABSTRACT

Phonograph system with tensioned wire coupling between a needle engaging a drum-type record and a loudspeaker, and including a speed controller having a pair of coaxial conical members with a viscous liquid therebetween, the outer member being driven by the drum which carries the record and the inner member being driven by the outer member through the viscous liquid.

United States Patent [72] Inventors Royal V. Jones, Jr.

Waltham; Clayton H. Allen, Wellesley; Colin G. Gordon, Bedford, Mass.

[21] Appl. No. 828,036

Division of Ser. No. 615,537. Feb. 13,1967, Pat. No. 3,480,283.

[22] Filed Mar. 5,1969

[45] Patented Mar. 30, 1971 [73] Assignee Bolt Beranek and Newman Inc.

Cambridge, Mass.

[54] PHONOGRAPH SYSTEM 2 Claims, 1 Drawing Fig.

Primary ExaminerDuane A. Reger AttorneyRines and Rines ABSTRACT:Phonograph system with tensioned wire coupling between a needle engaginga drum-type record and a loudspeaker, and including a speed controllerhaving a pair of coaxial conical members with a viscous liquidtherebetween,

[52] US. Cl 1851/220 the outer member being driven by the drum whichcarries the 46/ll7.274/17 record and the inner member being driven bythe outer [51] Int. Cl ..F16d 57/00 memberthrough theviscousliquid.

I6 I21 I2 IO 4 8 P 4! I d 7 \4 1 i sy so 2 234 7 5 g *Jfiun 3 "4" R I6 i20 b g s so I AW I \s f Is 6 EA 5% M 1 21 1:! l 9 J I, -34 11 PatentedMarch so, 1971 3,512,473

5" n 5' I8 I 6 2 3' 5 I BY (1M1 W ATTORNEYS rnonoonxrn SYSTEM This is adivision of application Ser. No. 615,537, filed Feb. 13, 1967 now US.Pat. No. 3,480,283.

The present invention relates to phonograph systems, being moreparticularly directed to self-powered sound-reproducing systems ofcompact and inexpensive construction for such applications assound-producing toys and the like; it being understood, however, thatcertain of the novel features of the invention are more broadlyapplicable to other types of soundreproducing systems as well.

Dolls and other toys and similar devices have previously been equippedwith small phonograph mechanisms of the selfpowered type wherein aneedle is mechanically coupled to a sound-reproducing loudspeaker devicesuch that by the pulling of a drawstring or the like, a spring device isenergized to power the movement of a phonograph record against theneedle. Prior art devices of this type have often required the use ofcircular record discs which, in combination with the requisite needlemounting structures, have introduced serious limitations in the numberand length of messages that may be recorded on a small size record andhave introduced problems in terms of the quality of reproductionresulting from varying groove speeds and the like. Such devices havealso required in some cases the use of viscous coupling mechanismsbetween the needle and the loudspeaker for permitting movement of theneedle relative to the record while yet allowing sound energy to betransmitted between the two. Such constructions, however, introducecomplexities and limitations into the acoustic transmission path betweenthe needle and the soundrepi'oducing loudspeaker. In addition, prior artrecording devices have also been subject to the disadvantage that theposition where the needle plays upon the disc record after eachsuccessive operation of the spring-tensioning device is a matter ofrandom chance. In such system, therefore, the user has had no controlover message selection and is unable to select different messages atwill.

An object of the present invention, accordingly, is to provide a new andimproved phonograph apparatus of the abovementioned type which shall notbe subject to any of the previously described disadvantages, but that,to the contrary, removes the inherent restrictions accompanying the useof disc records and, if desired, the uncertainties of selection ofdesired recorded messages thereon.

A further object is to provide a novel sound-reproducing apparatus ofmore general utility as well.

Other and further objects will be hereinafter delineated, being moreparticularly set forth in the appended claims.

In summary, the invention contemplates the use of a preferablycylindrical drum record provided on its exterior surface with aplurality of circumferential or helically spiralled recorded grooves,preferably recorded in the lateral mode and representing multiplemessages. A sound-reproducing loudspeaker means is provided at thebottom end of the drum. A needle holder is mounted outside the drum in amanner that allows it to slide parallel to the drum axis. It is normallypressed toward the drum to hold the needle within the record grooves.The vibrations transmitted to the needle holder from the recordedgrooves are conveyed via Coulomb friction to a tensioned wire and thenceto the loudspeaker. The tensioned wire is held between the loudspeakerand a tensioning spring. It rests against the needle holder but allowsthe needle holder to slide relative to it for positioning the needle inthe groove and for allowing the needle to track freely. The wire,furthermore, is of configuration that folds back upon itself in that itruns up the outside of the cylinder, then along a radius and down theaxis of the cylinder. This change in direction is achieved withinsignificant loss of vibration transmission by a unique rocker armdevice. A carriage is provide movable laterally with respect to the drumupon the operation of a tensioning drawstring or the like which not onlyserves to tension the drive means for the drum, but also in moving thecarriage serves to move the needle out of engagement with and away fromthe drum record grooves during the operation of the tensioning of thespring drive means. Preferred constructional details and novelsubcombination features particularly suited to the combination of thecomplete apparatus but useful also apart from the complete system, arehereinafter more fully explained.

The invention will now be described with reference to the accompanyingdrawing, the single FIGURE of which is aperspective view, partlysectionalized to illustrate details of construction, and showing theinvention in a preferred form.

A substantially cylindrical drum record 1 is carried at the lower end ofa cylindrical drum carrier 3 rotatable by a driving reel 5 about anaxially disposed hollow shaft 5 bottomed at 5" under a transversecentral plate 3. The driving reel 5 is powered by a spring Tshown in thepreferred form of the wellknown negator"-type spring. The mechanicalsystem, and particularly the hollow shaft 5', supporting the drumcarrier 3, and the spindle carrying the spring reel 7 is supported uponan outer support frame 10 extending external to the lateral walls of thedrum support 3 and over the top thereof. The spring 7 is tensionedthrough the pulling of a drawstring or the like 9 wound within a groove20 at the upper end of the drum carrier 3. As the draw string 9 ispulled, the spring 7 becomes wound upon the drive reel 5. Uponrelease'of the spring 9, the spring thus wound upon the drive reel 5causes the drum carrier 3 to rotate in one direction, say, to the right,so that the record grooves 1' circumferentially helically spiralled inthe external surface of the record drum .1 are moved in one directionpast a phonograph needle 11 carried in a needle holder 11'. The pullingof the spring 9 will, of course, move the drum-carried record grooves lin the opposite direction (to the left) for rewinding purposes.

The needle holder 11 is shown mounted within a slot 13 in a carriagesupport bracket 15, extending from the right-hand side of the apparatus(as illustrated in the drawing) over the top thereof, above the frame10, such that the needle is constrained to move up and down in adirection parallel to the axis of the drum 1. The carriage support 15 ismounted on the support frame 10 in a manner later explained, such thatit may be moved laterally with respect to the drum structure 1,3 and itsaxis upon the pulling of the string 9, so that the needle 11 ispermitted to disengage the record grooves 1' and drop downward away fromthe drum record grooves under the influence of a reset spring 21. Asbefore stated, this action will occur at the same time that the spring 7is being tensioned upon the drive reel 5. A return spring 17 carriedbetween the carriage bracket support 15 and the support frame 10 of theapparatus returns the carriage so that the needle 11 is engaged withinthe record grooves 1' at some circumferential position along the drumdependent upon the extent to which the drawstring 9 has been pulled.

The recorded messages upon the drum record 1 are preferably carried in anumber of successive individual grooves, all of which start at oneregion of the drum, each, however, at a different circumferentialposition, and which spiral along the drum to the opposite regionthereof. The user, by pulling the drawstring 9 different predeterminedextents, as shown by the calibrations 9', may therefore preselect thedesired record groove and thus the desired message that is to be played.The calibrations 9' may be color-coded or otherwise indicative of thedifferent messages.

In order to obviate the before-described problems in connection withcoupling the mechanical vibrations produced in the needle, through itsengagement with the record grooves 1, to a sound-reproducing loudspeaker2 disposed at the bottom end of the drum, and without the necessity forthe viscous coupling mechanisms and other devices of the, prior artbefore, referred to, a novel sound-coupling system is provided. Thisinvolves a small diameter wire 4 that is mounted under tension between aspring 6 at the bottom of the slot 13 in the carriage support 15 and theloudspeaker 2. The tensioned wire 4 rests against the needle holder 11'with some positive pressure. Vibrational energy thatis transmitted tothe needle holder 11 from the laterally recorded grooves 1, via theneedle 11, is

passed to the tensioned wire 4 as a longitudinal vibration by Coulombfriction which limits small amplitude movement between the needle holder11' and the tensioned wire. This construction, on the other hand,permits the large relative movements that are required for tracking andresetting purposes. The tension wire 4 thus frictionally presses againstthe stylus or needle-holding mechanism 11' with the needle engaging thegrooves 1'. It is this frictional force which carries the vibrationalsignal from the record grooves l to the wire 4 and then by means of thewire 4 to the loudspeaker 2 with negligible loss of signal. It will benoted that this type of coupling avoids the losses that inherentlyappear in prior-art viscous and other sliding coupling mechanisms. Thisconstruction, moreover, compensates for warping and eccentricities andthe like in the record, and minimizes the necessity for manufacturingtolerances of any high order, thus enabling the device to be built atvery low cost for such purposes as toys and the like, if desired.

This method of coupling also avoids many of the disadvantages of suchprior art devices, and, particularly, allows the needle to be remotelypositioned from the loudspeaker. The resonances of conventionalmechanical coupling structures in the audible frequency range areavoided since the thin wire 4 has a very small mass; and, when heldunder a high degree of tension, introduces mechanical resonances in itslongitudinal, driving direction which are at highfrequencies lyingoutside the required reproducing range. The tensioned wire 4 is Isusceptible to lateral resonance vibrations which lie in the audiblefrequency range, but these are poorly coupled to motion in thelongitudinal driving direction and are easily damped out by a closefitting sleeve of damping material 18, disposed about the portion of thewire 4 within the hollow shaft 5, between the later-described rocker arm8 and the speaker 2. The resonance of the system is thus controlledexclusively by the sound-reproducing loudspeaker 2 and the spring 6.

A further unique feature resides in the means by which the tensionedwire 4 is carried around a corner so that it may pass from the needlecarrier 11, on the outside of the drum, to the loudspeaker 2, on theinside of the drum. This is achieved with insignificant loss ofvibrational energy by the before-mentioned rocker arm 8, pivoted on theupper surface of the carriage support 15 and carrying the substantiallyradially inwardly extending portion of the tensioned wire 4 so that itmay bridge between the point 4' outside the periphery of the drum wherethe wire extends upward from the needle holder 11' adjacent the side ofthe drum and the point 4" on the axis of the drum where the wire passesaxially downward towards the loudspeaker 2.

Through this construction, and the particular positioning of the partsas above described, a very compact and inexpensive system is producedavoiding many of the disadvantages previously mentioned as inherent inprior art devices. As an example, a dozen three-second recordings canreadily be provided on a recording drum surface 1, about one-half inchlong and about l-iinches in diameter, rotated at a speed of about onerevolution per second. Unlike disc records, it is observed that thegroove speed is a constant, thus introducing a relatively high degree ofsimilar reproducing quality for all messages and from beginning to endof each message.

The carriage support 15 is preferably supported from the support frame10 upon small ball bearings 12 disposed in recesses 10' in the uppersurface of the frame 10 and in corresponding ball rollways 12' intheundersurface of the carriage 15. The ball rollways 12' in thecarriage also serve to stiffen the structure. The right-hand ball roller12 is preferably located as shown, close to the pivot point P of therocker arm 8 in order to give maximum support to the rocker arm. Thesupport frame 10 also serves to support the loudspeaker 2 at its lowerend by means of a clamping ring 14.

The grooves l are laterally recorded such that the needle 11 is causedto vibrate vertically up and downward in the direction of the tensionwire 4. The tension wire is by this means highly insensitive to "hilland dale" motions such as might be caused by scratching, dirt, etc. Itshould be noted that when the needle 11 is removed from contact with thegrooves 1 by operation of the pull drawstring 9, it disengages from thetensioning wire 4, as well.

The speed of the drum structure 1,3 during its playing period iscontrolled by a viscous speed controller 16 which is connected orcoupled by an O-ring 16' passing within a groove 16" in the speedcontroller housing and circumferentially around the entire drum 3 withingroove 3". While the speed controller has utility apart from theparticular combination shown, it is particularly designed for and suitedto the purposes of the invention. Within the housing 16, a conicalrecess 30 is provided, receiving a similarly shaped coaxial cone member30 axially supported through sealed bearings at the top and bottom ofthe housing and rotatable within the recess I 30 with a viscous liquid,such as liquid silicones, in the space therebetween. Since the movementbetween the coaxial-conical surfaces 30 and 30 increases with speed, asthe housing 16 rotates with the drum 3 at an increased speed, the torquebetween the conical surfaces will. increase, balancing the torque of thespring 5 and thus acting to control the speed of the drum structure. Afurther feature of this construction resides in its inherentself-centering properties.

Further modifications will occur to those skilled in this art and allsuch are considered to fall within the spirit and scope of the inventionas defined in the appended claims.

We claim:

1. Apparatus having, in combination, rotatable means the speed of whichis to be controlled, and a speed controller including a pair ofviscous-coupled coaxial rotatable members the torque between whichincreases upon increase in relative speed, one of said members being anouter member comprising a housing having an internal conical surfacedefining a conical recess and the other of said members being an innermember comprising an external conical surface separated from the saidinternal conical surface by a viscous liquid, both the inner and outermembers being rotatably supported upon a frame, and means driven by saidrotatable means for driving the outer member and for driving the innermember through the viscous liquid.

2. Apparatus in accordance with claim 1, and in which said driven meanscomprises a continuous ring passing about said outer member.

1. Apparatus having, in combination, rotatable means the speed of whichis to be controlled, and a speed controller including a pair ofviscous-coupled coaxial rotatable members the torque between whichincreases upon increase in relative speed, one of said members being anouter member comprising a housing having an internal conical surfacedefining a conical recess and the other of said members being an innermember cOmprising an external conical surface separated from the saidinternal conical surface by a viscous liquid, both the inner and outermembers being rotatably supported upon a frame, and means driven by saidrotatable means for driving the outer member and for driving the innermember through the viscous liquid.
 2. Apparatus in accordance with claim1, and in which said driven means comprises a continuous ring passingabout said outer member.